Clinical study of naltrexone microspheres for injection on preventing relapse effect from opioid dependence

SHAO Wei; WU Hao; CHEN Lin-ping; CHEN Jin; WANG Jin-hua

Abstract：Objective:To evaluate the efifcacy and safety of naltrexone microspheres for injection on preventing relapse from opioid dependence. Methods:There were 24 participants collected in our study, who were heroin dependent patients (diagnosed by DSM-Ⅳ) without physical conditions between the age of 18 and 45 years with at least three times relapse and were voluntary for treatment. All the subjects were randomly divided into experimental group and control group. The participants in experimental group were administered naltrexone microspheres for injection once every four weeks, totally 5 doses, while participants in control group were dosed oral naltrexone daily for 20 weeks. A 4-week follow-up was performed after medication cessation. Efifcacy and safety were evaluated at 0, 2, 4, 8, 12, 16, 20, 24 weeks. Results: Each group was enrolled 12 heroin dependent patients. One subject did not show in any follow-up and two subjects violated study protocol at visit 3 (the initiation of medication). There were total twenty-one subjects (experimental group, n=11;control group, n=l0) successfully completed in this study. In 4-24 weeks after administration, the negative percentage of urine samples of naltrexone microspheres for injection group were higher than that of control group and there was signiifcant difference between the control and experimental group at 8th week. There were ifve subjects (45.5%) in the experimental group ifnished the whole study, while two subjects (20.0%) in the control group completed this trial. The average time for dropout in experimental group was 18.55 weeks which was signiifcantly longer than that of control group, 11.40 weeks (P=0.033). Since 4 weeks after administration, the craving scores after one hour with administration in experimental group were substantially less than those of control group, which showed signiifcant differences at visit 5 (P=0.028) and visit 7 (P=0.042). Through the whole study, no serious treatment-related adverse events occurred. Conclusion:Compared with oral naltrexone, this study indicated that naltrexone microspheres for injection could decrease the relapse risk of heroin dependents, lessen their craving during abstinence, elevate their compliance and increase the time of voluntary therapy without increasing the risk of adverse events.